Equilibrium between Slag and Molten Iron in the Direct Alloying of Steel with Nb2O5-Bearing Slag

Equilibrium between slag and molten iron at 1600℃ was investigated for the direct alloying of steel with Nb₂O₆-bearing slag. The activity of niobium oxide in the slag was measured. The α_Nb2O5 is in the range of 10^-2-10^-4. Theδ_Nb2O5 is ranged in 10⁰-10^-2.Niobium partition decreases with the increase of[Si]% and CaO/SiO₂. When α_[0] and ΣFeO decrease, niobium partition decreases too. The δ_Nb2o5 and the ratio of γ_siO2 to γ_Nb2O5 decrease with the incre-ase of slag basicity. The suitable thermodynamic conditions in direct alloying of steel with Nb2O5-bearing slag have been found.     

熔融还原合成渣中碳还原Fe2O3的发泡特性参数

测定了Fe₂O₃在熔融还原合成渣中被碳还原时,还原气体产生泡沫渣的高度与时间的关系.由发泡特性参数方程计算了不同条件下的发泡特性参数,从而可以对熔融还原过程中由内生气源引起的发泡过程进行定量描述。为在铁浴中控制泡沫渣现象提供了必要的基础.     

DC-EAES-LF熔池电弧电渣加热过程的三维数值模拟

建立了非规范正交曲线坐标系下DC-EAES-LF炉电弧电渣加热过程三维数学模型,并进行联立耦合求解：速度场计算使用了矢性流函数方程和涡量输运方程;湍流模型采用引入Rechardson浮力修正项的k-ε双方程模型;温度场用非定常能量输运方程描述．现场测量的温度场与预报结果基本一致。     

碱式硫酸铬中微量Cr(6价)的测定

采用磷酸三丁酯萃取分离碱式硫酸铬中CrO2-4与Cr3+,CrO2-4被有机溶剂萃取后直接显色,通过分光光度法进行定量分析。方法加标回收率为97 6%～99 1%,变异系数1 9%。     

制备土聚水泥中若干因素的影响

为了解决碱矿渣胶凝材料收缩过大限制其应用的问题,将陶粒和陶砂掺入碱矿渣胶凝材料中形成碱矿渣陶粒混凝土.完成了252个碱矿渣陶粒混凝土试件的试验,考虑了水灰比、砂率、粉煤灰质量分数、水玻璃模数、氧化钠质量分数等关键参数对碱矿渣陶粒混凝土抗压强度和干缩率的影响.试验结果表明,碱矿渣陶粒混凝土的28 d边长为100 mm立方体的抗压强度为45~55 MPa,碱矿渣陶粒混凝土的28 d干燥收缩率为1.8×10^-4~4.4×10^-4.当水灰比、粉煤灰质量分数、水玻璃模数、氧化钠质量分数增大时,抗压强度减小,干缩率增大;砂率增大时,抗压强度增大,干缩率减小.

     

高Ru和高Cr对镍基高温合金组织稳定性的影响

在多组元的镍基高温合金中分别和同时加入高Cr和高Ru,经固溶处理后,在800~1100℃下进行10~1300h时效处理,观察组织并分析Ru、Cr以及二者交互作用对合金组织稳定性的影响.结果表明:在无Cr和Ru的合金中,经过1000℃/1300h时效处理后无TCP相析出;加入高Cr的合金仅20h就在晶界发现了TCP相,50h后在枝晶干出现TCP相;在1000℃时效,TCP相比其他温度更易析出.在同时加Cr和Ru的合金中,经过1000℃/1000h时效后并未发现TCP相的析出.这说明高含量的Cr促进了TCP相的形成,而高Ru的添加在高Cr合金中也能有效地抑制TCP相的析出,提高组织稳定性.     

Mn含量对铸造高铌TiAl合金组织和性能的影响

选择两种Mn含量不同的高铌TiAl合金Ti46Al8Nb2Mn0.2B和Ti46Al8Nb1.3Mn0.2B,通过热等静压(HIP)及后续热处理,结合组织和力学性能的分析,研究了Mn含量对高铌TiAl合金的组织和性能的影响.XRD和SEM背散射电子实验结果表明:Mn含量较高的Ti46Al8Nb2Mn0.2B合金,经热等静压及循环热处理,得到的双态组织较粗大,并且有少量脆性β相存在;Mn含量较低的Ti46Al8Nb1.3Mn0.2B合金,经热等静压后直接在双相区长时间保温处理,得到了细小的双态组织,并且完全消除了β相.室温拉伸实验表明,Mn含量的降低提高了Ti46Al8Nb1.3Mn0.2B合金的力学性能,其延伸率、屈服强度和断裂强度分别达到2.4%、548MPa和660MPa.断口形貌分析表明,室温下两种合金都属于解理断裂.     

镁锆砖的制备工艺参数与抗RH炉渣侵蚀的相关性

通过对比镁锆砖和镁铬砖抗RH炉渣侵蚀机理以及简化模型法,研究了镁锆砖的制备工艺参数与抗RH炉渣侵蚀的相关性.利用正交试验的方法分析了颗粒级配、助烧剂、烧结温度、氧化锆含量和氧化锆种类对镁锆砖抗渣性能的影响,确立影响镁锆砖抗渣性能的关键因素为烧结温度和氧化锆含量.在此基础上进一步分析烧结温度和氧化锆含量对镁锆砖抗渣侵蚀性能的影响.通过统计分析手段,利用中心复合设计,建立镁锆砖的抗侵蚀统计分析模型,并作响应曲面图形.     

Adsorption of Chromium (VI) Using an Activated Carbon Derived from Petroleum Coke Feedstock

This study aims to determine the main adsorption mechanism by which chromium (VI) is adsorbed onto the surface of a petroleum-coke sourced activated carbon, a feedstock not prevalent in current literature. The study also aims to produce an activated carbon adsorbent that is both cost-effective and efficient for the removal of chromium (VI) in neutral waters. The efficacy of thermally-treated petroleum coke-activated carbon and nitrogenated petroleum coke-activated carbon using ammonium chloride is compared to the efficacy of commercially available activated carbon. X-ray photoelectron spectroscopy of the activated carbons was obtained both before and after exposure to chromium (VI) for characterization of the materials and confirmation of chromium adsorption. The thermally-treated and nitrogenated activated carbons showed significant enhancement of chromium (VI) removal compared to the non-treated petroleum coke-activated carbon (22.4 mg/g, 21.9 mg/g, and 17.0 mg/g, respectively). However, there was no significant difference observed between the thermally-treated and nitrogenated materials. This indicates that the nitrogenation of the surface does not improve the adsorption capacity of the activated carbon, but rather the thermal treatment itself. X-ray photoelectron spectroscopy showed a significant increase in the alcohol functional groups on the surface of the activated carbon material as a result of the heat-treatment process; from 16.02 atomic percent in the non-treated activated carbon to 26.3 atomic percent in the thermally-treated activated carbon. The alcohol functional groups present on the surface allow for chromium (VI) to undergo reduction to chromium (III) under a similar mechanism to the well-known Jones Oxidation Reaction where the reduced chromium (III) species are then physisorbed to the surface of the activated carbon. XPS results are consistent with this as the chromium species present on the surface of the adsorbent is primarily Cr(OH)₃ (85.6% in the standard AC and 82.5% in the thermally-treated AC). Pseudo-first-order and pseudo-second-order kinetic modeling of the adsorbents indicate that they follow a pseudo-second-order reaction where the rate-limiting step is the chemical sorption of the adsorbate itself.     

40万t/年转炉钢渣蒸汽陈化处理生产线

介绍了针对国内某炼钢厂专门设计的40万t/年转炉钢渣蒸汽陈化处理生产线主要参数及工艺流程,对该生产线中的钢渣倾翻车、钢渣冷却搅碎车、转运车、蒸汽陈化釜等主要设备特点进行了阐述,同时对该生产线应用的冷却水量研究、搅碎辊轨迹优化等关键技术作了进一步的探讨。